Plasma Jet Electric Thrusters for Spacecraft

Our Vision:

Our vision is to design, build, and experimentally demonstrate a prototype pulsed plasma jet thruster targeted for orbital maneuvering, asteroid/comet rendezvous, orbital debris cleanup and interplanetary transportation. Our company, HyperV Technologies Corp., has extensive experience designing, building, operating, and deploying extremely high performance single-shot plasma accelerators of many different shapes, sizes, and power levels. These plasma jet accelerators have been developed for applications in fusion energy and high energy density plasma physics research [www.hyperv.com].

We believe this same basic pulsed plasma jet technology can be adapted to increase the robustness and decrease the cost of spacecraft electric propulsion, thus opening the door to many new exciting robotic and manned space missions. Our first step with this project is to successfully demonstrate repetitive operation as a thruster.

We invite you, the citizens of Earth, to join with us as we design, construct, test, and execute this demonstration. The culmination of this project will be an all-up, laboratory demonstration of our prototype thruster. You will be updated via our Kickstarter Blog, Facebook, Twitter and uploaded video of the firing posted to our website.

Our technical objectives for this thruster development project are to meet or exceed the following thruster performance goals:

Design and construct a high density gas fed plasma thruster operated at an average continuous input power level of about 1.0 kW

Achieve a specific impulse (Isp) of 2000 sec (which means an average exhaust velocity of about 20,000 m/s)

Operate at 5 pulses per second (5 Hz) for a minimum duration of one minute

A Plasma Jet What?:

A plasma accelerator is a device which forms a slug of hot, ionized particles, or plasma, and launches these plasma pulses at high velocity. Our plasma accelerators, one of which is shown in Figure 1, consist of two parts: A formation section and an acceleration section. The formation section forms and ionizes a plasma armature or slug from a source material and injects it into the next section. The acceleration section consists of a pair of straight parallel metallic electrodes separated by a pair of ceramic insulators. A large current is then driven through the electrodes and plasma armature, accelerating the plasma slug using the resultant self-generated magnetic Lorentz force. The performance of our existing single shot plasma accelerator designs has already been demonstrated [poster presentations from the 2009, 2010, and 2011 American Physical Society Division of Plasma Physics annual meetings www.hyperv.com/papers.html ]. We must now adapt this existing low cost, scalable technology to transform it into a repetitively pulsed, continuously operable, compact plasma thruster.

Why are plasma thrusters important for space travel?:

Spacecraft electric propulsion is extremely fuel efficient and dramatically reduces the amount of propellent mass and volume that a spacecraft needs to travel to and/or return from its destination in space. Because a spacecraft's size and weight are reduced, the overall cost of launching that spacecraft into orbit or onto an interplanetary trajectory is significantly reduced. Since the 1960's there have been nearly a dozen different types of electric propulsion thrusters which have been developed, some of which have already flown in space. Yet while many of today's modern communications satellites employ a variety of electric thrusters to maintain their precise orbits above earth, to date, only four robotic science spacecraft have flown missions using electric propulsion as the primary means to propel the spacecraft through deep space. Because of its great potential, NASA, which was the first to launch a deep space mission using electric propulsion, is using and continues to study electric propulsion for greatly expanded space missions in the future. For many future missions, electric propulsion is the only viable option. It is therefore imperative that we investigate all useful forms of electric propulsion, including pulsed plasma jet thrusters.

For fun here is a fascinating Walt Disney clip from around 1957 of a massive manned mission to Mars using electric propulsion as envisioned by Wernher von Braun: http://www.youtube.com/watch?v=3wIXZsbjIxA. Today we could also use solar panels instead of nuclear to generate the electrical power. Yes indeed, spacecraft electric propulsion has the potential to bring back the magic of the early years of space exploration!

So why bother to develop Plasma Jet Thrusters if there are other types of electric propulsion systems that have already flown in space?:

Because, quite simply, we think ours will be better! We believe our thruster technology has the potential to be just as efficient as existing electric thrusters (such as ion and Hall effect thrusters) and with similar specific impulse. But our advantages will be derived from a thruster that is less complex (and much more robust), which can use a variety of propellants including gases, inert plastics, and propellants derived from asteroids, Mars, the Moon, etc., It will also be far cheaper to build, and can be more readily scaled to larger sizes and very high power levels than current electric propulsion systems. Our plasma thruster technology should be scalable from a few kilowatts all the way up to megawatts of average power. The electricity which is needed to power electric thrusters would most likely come from new high performance solar panels, but could also utilize other compact energy sources. From a practical viewpoint for satellite design, our thruster will have much higher thrust per unit area than ion or Hall thrusters, thus taking up less room on the rear of the spacecraft.

Figure 3 : Open shutter image of an approximately 10 microsecond long plasma pulse in visible light.

Due to the
efforts of a number of private space companies, there is significant
potential for the cost to reach orbit to be significantly reduced,
but even these lower launch prices will still be expensive. This
means that once a spacecraft reaches Earth orbit, there is still a
need for more cost effective methods of in-space transportation.
That's where we come in. With our plasma thruster project we want to
work on reducing the cost of space transportation further by cutting
the mass and volume needed for spacecraft fuel, while increasing the
transportation capabilities of the spacecraft. Cheaper robust
spacecraft thrusters will serve as an enabler for daring low-cost
robotic and ultimately new manned space missions. These missions
could return samples from near-Earth asteroids, or support a more
ambitious effort to return samples from Mars and beyond.

Plus, since our
technology stems from our already scalable single-shot pulsed plasma
accelerators, our plasma thruster design also promises to be
scalable, including up to sizes large enough to support future large
interplanetary manned space missions. We believe our thruster
technology will be best suited for spacecraft with minimum masses of
100 kg (about 220 lbs) and larger.

Why
you should be involved:

You should be
involved because not only are we offering to let you help us lay the
cornerstone for a new type of robust spacecraft electric propulsion
which is well suited for use in heavy robotic and manned
interplanetary space missions, but also because we are offering to
take you behind the scenes for the prototype development process. We
will be providing progress reports and status updates to the
Kickstarter blog, and on Twitter, and the latest test results and
preliminary analysis will be available to our friends on Facebook,
including post-experimental summaries. You should also know that in
addition to our limited ticketed main firing event, we will be
hosting tours where you can stop by and see our facility. See our
laboratory! See our plasma accelerators! We are offering you a chance
to see plasma physics in action. Plus we are going to take some
really cool high speed photos of plasma which will also be available
to our backers.

So
who are we?

We are a team of
three scientists, Dr. Doug Witherspoon, Dr. Andrew Case, Dr. Sam
Brockington, and an energy & space entrepreneur, Chris Faranetta who quite
frankly build the world's best plasma jets for nuclear fusion and
plasma physics research. But did we mention that we really, really
like space too and we would like to see the cost and complexity of
deep space exploration come down so that lots more cool manned and
un-manned missions can happen? Our company is called HyperV
Technologies Corp. The HyperV part stands for HyperVelocity - we are
all about moving plasma fast, really fast, I mean hyperfast! Check
out our website at www.hyperv.com where we talk about the cool
stuff we've done in plasma physics research funded through
competitive government research grants.

Figure 4: HyperV Technologies' plasma jet testing facility.

HyperV
Technologies Corp is based in Chantilly, Virginia USA. We have a
machine shop from which our existing accelerator designs and high
power switches have already been produced. Our 9000 square foot
facility contains not one, but two fully functional very high
voltage/high vacuum laboratories, complete with high voltage
charge/dump control systems and high vacuum ( 1 microTorr) chambers,
and other experimental support. We have over 80 channels of 1-2
Gigasample per second state-of-the-art, computer-controlled, data
acquisition, and multiple high voltage charging supplies already
installed and operating. We also maintain an extensive suite of
plasma and pulsed power diagnostics, including ICCD fast-framing
cameras for high speed (nano second gate) photography, digital
cameras for long exposure color photography, photodiode arrays for
real-time streak photography, batteries of magnetic probes,
collimated optical and interferometric density diagnostics, as well
as apparatus for survey and high-resolution spectroscopic
measurements and other diagnostics for high-voltage high-current
measurements.

How
far along are you?

HyperV has
already designed, constructed, and operated multiple single-shot,
linear plasma accelerator configurations of several bore lengths and
bore cross-sections ranging from 3mm square to 50mm square and up to
30cm long. HyperV has working designs for both gas fed and ablative
capillary fed plasma accelerators. Adaptations of the gas fed designs
would be used for the thruster, but ablative concepts using simple
plastic as the “propellant” are also being explored.

Figure 5: A small 15cm long plasma accelerator similar in size to the proposed project thruster. This 2cm square bore uses boron nitride insulators to reduce wall ablation.

Existing
HyperV accelerators are already very compact. For example, the main
body structure of our 1 x 30 cm accelerator weighs in at about 2.5 kg
(5 lbs), and our existing 0.5x10 cm accelerators can be as little as
0.25 kg(0.5 lbs). And since none of these devices was especially designed for
low mass, we can probably reduce them another factor of two lower!

The principal
focus of this new project would be on adapting one of our existing
minirail accelerator designs to a 5 Hz repetitively pulsed system
capable of producing 2000 sec specific impulse. We have a plan for
the first round of testing, including an initial design concept for the
driver circuit, an initial concept for the plasma thruster, and
estimates for diagnostic requirements, and the modifications
necessary to support burst mode operation and data acquisition.

The next step
is to finalize the first experiment plans, construct the device,
prepare the diagnostics necessary for the first test, and perform the
tests.

Figure 6: Dr. Witherspoon holds a 15cm long plasma accelerator similar to that seen in the photo above showing size comparison between a thruster and a group of three of our high performance single shot accelerators.

Funding
Goals

Our
initial target funding goal is $69,000. At this level of support we
will be able to achieve the following:

1)
We will design, build and test a prototype plasma jet thruster that
can operate repetitively. This will be a proof-of-principle
demonstration that our plasma jet accelerators can indeed be
transformed into a working plasma thruster.

2)
We will demonstrate basic repetitive operation of the thruster at 5
Hz, i.e. 5 pulses per second. A space qualified thruster would
ultimately operate at many hundreds of pulses per second, even as
much as 1000 pulses per second, in order to provide an average steady
thrust with high Isp. Our present plasma accelerators can fire once
every few minutes, but operate at extremely high performance, i.e.
about 8000 micrograms of argon at 50 km/s. The repetitive thruster will
operate at perhaps only 10 micrograms of argon (or xenon) at 20 km/s.
We will accomplish this by reducing the size of the accelerator and
reducing the pulsed drive current from 600,000 amps, down to only
about 10,000 amps. This will allow us to operate at high rep rates.

3)
We will make basic measurements of thrust using a ballistic pendulum.
This is accomplished by directing the plasma slug onto a pendulum
where the impact causes the pendulum to recoil. Measuring the amount
of recoil tells us how much momentum was in the jet. By using other
optical techniques to measure the velocity we can then infer the mass
of the plasma jet. Once we know the mass and velocity, we can
calculate things like the specific impulse and average thrust.

4)
We will make additional basic plasma diagnostic measurements so we
know what's going on in the thruster. These will include things like
measuring the density of the plasma using a laser interferometer, and
measuring its temperature using spectroscopic techniques. Using very
fast framing cameras in which the shutter can open and close in 50
billionths of a second allows us to get snapshots of the plasma
plume. We'll also use open shutter photography with a DSLR camera to
observe the plume evolution exiting from the thruster nozzle. This is
going to make some really cool high speed pictures of plasma blasting
out from the thruster.

5)
Using all these diagnostic measurements will allow us to make
calculations of the overall thruster efficiency, Isp, and
thrust/power ratio – parameters critically important to the success
of the thruster.

Figure 7: One of the really cool items available only to our backers.

That's
going to be a lot of work for our basic goal of $69,000, but we are
confident of success. This will provide the basic demonstration and
data we need to confirm that our plasma jet units can indeed function
successfully as a high performance thruster. Our hope, of course, is
that we will receive more than that from you our supporters. If that
occurs we have a plan for advancing the thruster development process
even further. We intend to go all the way with this thruster and we'd
love to see you come along with us!

If we exceed the initial funding goal, we will be able toachieve even more!

For example, at the $100,000 level, we will also be able to:Build a simple thrust stand to make direct continuous thrustmeasurements, to compare with the ballistic pendulum measurements. Thiswill be important for definitively measuring the thrust as opposed tocalculating it from other parameters. We will also be able to build andtest a breadboard energy recovery circuit. This circuit is crucial formaximizing the long term overall efficiency of the thruster. At the endof each thruster pulse, there is some remaining energy stored in themagnetic field of the current pulse just as the plasma blob exits thenozzle. We need to recover this energy and reuse it on the next pulseto maximize the overall efficiency of the thruster. We plan to design acircuit that stores this energy capacitively so that the voltage forthe next pulse only needs to be “topped-off” instead of charged all theway from zero. We'll also be able to increase test run time and thusgather more data for future design modifications to the thruster.

At the $150,000 level, in addition to the above accomplishments, wewill also be able to: Add additional pumping and cooling features toallow even longer run times. Like all electric thrusters, our thrusterwill ultimately need to incorporate some heat management features toensure it does not overheat when operating for months at a time. Wewould also be able to add a functional energy recovery circuit (notjust a breadboarded circuit) to the thruster and operate them togetherto demonstrate an high efficiency system. Our goal is an efficiency ofabout 50%, meaning the kinetic energy of the thruster exhaust is 50% ofthe amount of electrical energy delivered by the power supply.

At funding levels above $150,000, we would be able to accomplishfurther tasks such as: 1) Perform more extensive lifetime testing ofthe thruster components, 2) Build an improved thrust stand withimproved fidelity, 3) Perform test runs with xenon gas (which is moreexpensive than using argon gas), and 4) Test the thruster entirely invacuum, which provides a better thermal test of the hardware in anactual simulated working space environment. This will be important forlearning how best to incorporate cooling features.

Risks and challenges

The risks and challenges are mainly technical, but the technical risks are low for achieving the stated project demo goals of 5 Hz, 1 kW, 2,000 sec specific impulse operation. The specific impulse goal of 2,000 sec is pretty straightforward, since we have already achieved over four times that number in our previous work. The main risk is actually getting a repetitive pulsed thruster working smoothly and dissipating the heat generated from the drive current. For the 5 Hz burst mode planned for the project demo, heating should not be a problem as long as we limit the run time to a few minutes. If it survives that, we'll try running it for longer duration times to learn more about its thermal characteristics. The external drive circuitry will need to be modified so that the capacitors are charged and discharged in a quasi-continuous manner, but again, this is relatively straightforward. We feel the parameters set forth in this project are sufficient to prove the thruster is worthy of further development. We plan to build an energy recovery circuit to recycle the stored magnetic field energy at the end of the pulse that would otherwise be wasted, but that effort is beyond the resources of our initial funding goal. Such a circuit would be able to increase the overall efficiency of the thruster to a level that is attractive for a space qualified system. None of the technical issues really affect whether we can pull off the project demonstration, but only affect what specific parameters we might achieve for that demo. We plan to aggressively push the parameters as far as we can during the project.

Kickstarter is not a store.

Pledge US$ 50 or more
About $50

The “Lagrange point 1 support kit”, you have reached a point in space where neither the earth nor the moon can pull you back down. This supporter kit includes: a personalized thank you certificate, our cool project sticker, an embroidered project patch, just like the ones they use at NASA, and a 10 image screen saver which contains really sublime, original high speed images of plasma blasting out of our jets.

Kickstarter is not a store.

Pledge US$ 75 or more
About $75

Around the far side of the moon and back, now you are going places. The “Lunar Free Return” supporter package gives you a personalized thank you certificate, our cool project sticker, an embroidered project patch and our very cool project t-shirt.

Kickstarter is not a store.

Pledge US$ 100 or more
About $100

We would like to give you the moon for your support! But uh, would you settle for the “Lunar Orbit” supporter package? This package comes with a personalized thank you certificate, our cool project sticker, an embroidered project patch, a neat 30 image screen saver/desktop collection of HyperV original high speed glowing plasma jet plumes and our awesome plasma blast mouse pad.

Kickstarter is not a store.

Pledge US$ 150 or more
About $150

It's like the thrill of being on the lunar surface but without all that dust. The “Lunar Surface” supporter package includes: a personalized thank you certificate for your support, our cool project sticker, an embroidered project patch, our very cool project t-shirt and the 30 image screen saver/desktop collection of HyperV original high speed glowing plasma jet plumes.

Kickstarter is not a store.

Pledge US$ 200 or more
About $200

What happens on the lunar surface does not always stay on the moon. The “Lunar Surface Return” supporter package comes with a personalized thank you certificate for your vital support, a cool project sticker, an embroidered project patch, a quality base ball cap emblazoned with our embroidered project patch, and very cool project t-shirt.

Kickstarter is not a store.

Pledge US$ 325 or more
About $325

Cleaning up space is a tough job that requires a lot of energy and we think we have the delta-V to do it. The “Earth Orbit clean-up” supporter package comes with a personalized thank you certificate, our cool project sticker, and embroidered project patch. Also included are a quality baseball cap emblazoned with our embroidered project patch, our very cool project t-shirt, the plasma blast mouse pad, a 30 image screen saver/desktop collection and a very rugged HyperV engraved logo Mini Mag-Lite.

Kickstarter is not a store.

Pledge US$ 400 or more
About $400

You are so special to us that we have put you in your own orbit around the sun. The “Solar Orbit” supporter package comes with a personalized thank you certificate, our cool project sticker, an equally cool embroidered project patch, a quality baseball cap with an embroidered project patch, our very cool project t-shirt, the plasma blast mouse pad, the 30 image screen saver/desktop collection and the tough HyperV engraved logo Mini Mag-Lite.

Kickstarter is not a store.

Pledge US$ 500 or more
About $500

It's our goal to someday help payloads escape to Mars on a regularly scheduled basis and your support should work to make it possible. The “Mars Escape Velocity” supporter package includes a personalized thank you certificate, our cool project sticker, an official embroidered project patch, a quality baseball cap with our embroidered project patch, a very cool project t-shirt, the plasma blast mouse pad, the 30 image screen saver/desktop collection and the HyperV engraved logo Mini Mag-Lite. Also we will include an 11” x 14” framed personalized signed color photo of a unique plasma butterfly 'galaxy' image. We will also provide a guided tour of our laboratory, plus a discussion of our plasma jet research and the potential of plasma jet thrusters in space propulsion.

Kickstarter is not a store.

Pledge US$ 1,500 or more
About $1,500

Wow, thank you so much for helping us arrive at our goal and here is what arrival at the “Mars Orbit” supporter package includes: a personalized thank you certificate, our cool project sticker, an embroidered project patch, a quality baseball cap emblazoned with our embroidered project patch, our very cool project t-shirt, the plasma blast mouse pad, an original 30 image screen saver/desktop collection, and HyperV engraved logo Mini Mag-Lite. This package also includes an 11” x 14” framed personalized signed color photo of our plasma butterfly 'galaxy' image, a guided tour of our laboratory, discussion of our plasma jet research and the potential of plasma jet thrusters in space propulsion and we'll take you out to a nice lunch. We will also add to all of this really great stuff a custom made mounted scale model mock-up of our plasma jet thruster with a commemorative plaque.

Kickstarter is not a store.

Pledge US$ 2,500 or more
About $2,500

Your support via the “Mars Phobos Landing” package level is fantastic and really appreciated. For your support this package includes a personalized thank you certificate, our cool project sticker, an awesome embroidered project patch, a quality baseball cap with our embroidered project patch, our very cool project t-shirt, the plasma blast mouse pad, a 30 image screen saver/desktop collection and a HyperV engraved logo Mini Mag-Lite. Also we will include an 11” x 14” framed signed color photo of our plasma butterfly 'galaxy' image, a custom made mounted scale model mock-up of our plasma jet thruster with a commemorative plaque. Plus a guided tour of our laboratory, discussion of our plasma jet research and the potential of plasma jet thrusters in space propulsion. Also included is a seat to watch our plasma jet firing event from the safety of our observation gallery. Then following the firing event we'll take you out to a nice lunch.

Kickstarter is not a store.

Pledge US$ 5,000 or more
About $5,000

Returning samples from Phobos would be quite a feat and thanks to you it could happen some day in the near future! The Mars Phobos Sample Return supporter package includes a personalized thank you certificate, our cool project sticker, an embroidered project patch, a quality baseball cap with our embroidered project patch, our very cool project t-shirt, the plasma blast mouse pad, the 30 image screen saver/desktop collection and a HyperV engraved logo Mini Mag-Lite. We will also include an 11” x 14” framed personalized signed color photo of our plasma butterfly 'galaxy' image, and a custom made mounted scale model mock-up of our plasma jet thruster with a commemorative plaque. Plus this package also includes a guided tour of our laboratory, discussion of our plasma jet research and the potential of plasma jet thrusters in space propulsion. You will also be invited to our plasma jet firing event and participate in our secure screen room, and help us monitor plasma jet performance, plus we'll take you out to a nice lunch afterwards.

Kickstarter is not a store.

Pledge US$ 10,000
About $10,000

Samples from Phobos is one thing but samples from the surface of Mars takes this metaphor for your support to a whole now level. The “Mars Sample Return” supporter package includes a personalized thank you certificate, our cool project sticker, an embroidered project patch, a quality baseball cap with our embroidered project patch, our very cool project t-shirt, the plasma blast mouse pad, a 30 image screen saver/desktop collection and a HyperV engraved logo Mini Mag-Lite. Also we will include an 11” x 14” framed personalized signed color photo of our plasma butterfly 'galaxy' image, a custom made mounted scale model mock-up of our plasma jet thruster with a commemorative plaque. Plus this package also includes a guided tour of our laboratory, discussion of our plasma jet research and the potential of plasma jet thrusters in space propulsion, an invitation to our plasma jet firing event to participate in test firing in our secure screen room and help us monitor plasma jet performance data monitoring equipment. Then after the firing we'll take you out to a nice lunch.

But there is more, this support package also includes responsible and constructive naming rights for this Kickstarter project thruster. The rights include sponsor signage on the wall of our vacuum tank to ensure your name appears in images and videos taken of the Kickstarter project experiment.